The principle objective of this application is to identify the impact on cognitive function of specific neuropathological changes found in Alzheimer's Disease. The study will be conducted in collaboration with a group of neurologists from the Maine Medical Center. Participating AD patients will serve as candidates for further research; efforts will be made to follow each patient to autopsy to expand an AD brain data bank. To determine whether cognitive integrative functions are impaired in AD, multiple aspects of grouping processes will be compared between AD patients and demographically-matched control subjects. Comparisons will also be made between young and elderly healthy control subjects to assess the effects of aging on these capacities. Analyses will be made of processes that mediate the segregation and association of discrete elements, the processing of identifiable configurations, and the processing of global relationships.